Convocation gem missing as purchase option from vendors

According to https://pathofexile.fandom.com/wiki/Convocation I should be able to buy the mentioned gem from either Clarissa or Siosa.

Sadly neither offers it to purchase. What am I doing wrong? (Maramoa doesn't have reward to pick too.)

Thank you kindly!

I'm wondering if it would be better to place this on the blue gem where there is a space after lightning conduit?

should definitely be shown in both tabs imho

came here via google looking if it's a bug or not that I can't buy convocation, apparently I just needed to check the misc/white tab